2017-16776. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede Airworthiness Directive (AD) 2012-12-05, which applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. AD 2012-12-05 currently requires repetitive inspections for cracking under the stop fittings and intercostal flanges and for cracking of the intercostal web, attachment clips, stringer splice channels, frame, reinforcement angle, shear web, frame outer chord and inner chord; a one-time inspection to detect missing fasteners; repetitive inspections of the cargo barrier net fitting for cracking; repetitive inspections for cracking of the stringer S-15L aft intercostal; and repair or corrective action if necessary. Since we issued AD 2012-12-05, we have received reports of additional cracking in locations not covered by the inspections in that AD. For certain airplanes, this proposed AD would add new repetitive inspections of certain areas of the frame inner chord, and applicable on-condition actions. We are proposing this AD to address the unsafe condition on these products.

DATES:

We must receive comments on this proposed AD by September 29, 2017.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740; telephone [phone]; Internet https://www.myboeingfleet.com. You may view this referenced service information at the FAA, Transport Standards Branch, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0774.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0774; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Galib Abumeri, Aerospace Engineer, Airframe Section, FAA, Los Angeles Aircraft Certification Office (ACO) Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: [phone]; fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2017-0774; Product Identifier 2017-NM-036-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://,www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On June 4, 2012, we issued AD 2012-12-05, Amendment 39-17084 (77 FR 36139, June 18, 2012) (“AD 2012-12-05”), for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. AD 2012-12-05 superseded AD 2004-09-09, Amendment 39-13598 (69 FR 23646, April 30, 2004); and AD 2009-16-14, Amendment 39-15987 (74 FR 38901, August 5, 2009). AD 2012-12-05 requires repetitive inspections for cracking under the stop fittings and intercostal flanges and for cracking of the intercostal web, attachment clips, stringer splice channels, frame, reinforcement angle, shear web, frame outer chord and inner chord; a one-time inspection to detect missing fasteners; repetitive inspections of the cargo barrier net fitting for cracking; repetitive inspections for cracking of the stringer S-15L aft intercostal; and repair or corrective action if necessary. AD 2012-12-05 resulted from reports of cracking of the station (STA) 348.2 frame above the two outboard fasteners attaching the frame inner chord and door stop fittings, and in the outboard chord at stringer S-16L. AD 2012-12-05 also resulted from reports of missing fasteners in the STA 348.2 frame inner chord. We issued AD 2012-12-05 to detect and correct fatigue cracking of the intercostals on the forward and aft sides of the forward entry door cutout, which could result in loss of the forward entry door and rapid decompression of the airplane.

Actions Since AD 2012-12-05 Was Issued

Since we issued AD 2012-12-05, we have received reports of additional cracking in the STA 351.2 frame inner chord at stringer S-17L, at the fastener hole location common to the frame inner chord, door sill, and shear web. The cracks were reported on Model 737-300 and -500 airplanes that had accumulated between 40,600 and 65,500 total flight cycles. The STA 351.2 frame inner chord at stringer S-17L is hidden under the shear web and the door sill; therefore, any cracking at this location cannot be visually detected.

Related Service Information Under 1 CFR Part 51

We reviewed Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016. The service information describes procedures for, among other actions, repetitive inspections of the fastener holes in the STA 351.2 frame inner chord at stringer 17L, and applicable on-condition actions. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would retain all requirements of AD 2012-12-05. Although this proposed AD does not explicitly restate the actions in Boeing Alert Service Bulletin 737-53A1240, Revision 1, dated June 29, 2010, that are part of the requirements of AD 2012-12-05, this proposed AD would retain those requirements. Those requirements are referenced in the service information identified previously, which, in turn, is referenced in paragraph (p) of this proposed AD. Paragraph (p) of this proposed AD would require accomplishment of the actions identified as “RC” (required for compliance) in the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016, except for any differences identified as exceptions in the regulatory text of this proposed AD.

For information on the procedures and compliance times for Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016, see this service information at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0774.

Costs of Compliance

We estimate that this proposed AD affects 411 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspections for cracking under the stop fittings and intercostal flanges [retained actions from AD 2012-12-05] (411 airplanes)	18 work-hours × $85 per hour = $1,530 per inspection cycle	$0	$1,530 per inspection cycle	$628,830 per inspection cycle.
Inspection of areas forward of the aft entry door [retained actions from AD 2012-12-05] (411 airplanes)	2 work-hours × $85 per hour = $170 per inspection cycle	0	$170 per inspection cycle	$69,870 per inspection cycle.
Inspection of areas aft of the forward entry door [retained actions from AD 2012-12-05] (411 airplanes)	1 work-hour × $85 per hour = $85 per inspection cycle	0	$85 per inspection cycle	$34,935 per inspection cycle.
Inspection for missing fasteners [retained actions from AD 2012-12-05] (411 airplanes)	1 work-hour × $85 per hour = $85	476	$561	$230,571.
Inspection of fastener holes (new proposed action) (160 airplanes)	27 work-hours × $85 per hour = $2,295 per inspection cycle	0	$2,295 per inspection cycle	$367,200 per inspection cycle.

We estimate the following costs to do any necessary repairs that would be required based on the results of the inspections. We have no way of determining the number of aircraft that might need these repairs:

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Repair of cracking done in accordance with Boeing Alert Service Bulletin 737-53A1240	24 work-hours × $85 per hour = $2,040	$11,856	$13,896

We have received no definitive data that would enable us to provide cost estimates for the other on-condition corrective actions specified in this proposed AD.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

This proposed AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes to the Director of the System Oversight Division.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that the proposed regulation:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

(3) Will not affect intrastate aviation in Alaska, and

(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2012-12-05, Amendment 39-17084 ( 77 FR 36139, June 18, 2012), and adding the following new AD:

The Boeing Company: Docket No. FAA-2017-0774; Product Identifier 2017-NM-036-AD.

(a) Comments Due Date

The FAA must receive comments on this AD action by September 29, 2017.

(b) Affected ADs

This AD replaces AD 2012-12-05, Amendment 39-17084 (77 FR 36139, June 18, 2012) (“AD 2012-12-05”).

(c) Applicability

This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.

(d) Subject

(d) Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

This AD was prompted by reports of cracking of the station (STA) 348.2 frame above the two outboard fasteners attaching the frame inner chord and door stop fittings, and in the outboard chord at stringer S-16L; missing fasteners in the STA 348.2 frame inner chord; and additional cracking in locations not covered by the inspections in AD 2012-12-05. We are issuing this AD to detect and correct fatigue cracking of the intercostals on the forward and aft sides of the forward entry door cutout, which could result in loss of the forward entry door and rapid decompression of the airplane.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Retained Initial Compliance Time for Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes, With No Changes

This paragraph restates the requirements of paragraph (i) of AD 2012-12-05, with no changes. For all Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, as identified in Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: Before the accumulation of 15,000 total flight cycles, or within 4,500 flight cycles after November 1, 2005 (the effective date of AD 2005-20-03, Amendment 39-14296 (70 FR 56361, September 27, 2005) (“AD 2005-20-03”)), whichever occurs later: Do the inspections required by paragraphs (i) and (j) of this AD.

(h) Retained Initial Compliance Time for Model 737-200C Series Airplanes, With No Changes

This paragraph restates the requirements of paragraph (j) of AD 2012-12-05, with no changes. For all Model 737-200C series airplanes, as identified in Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: Before the accumulation of 15,000 total flight cycles, or within 4,500 flight cycles after September 9, 2009 (the effective date of AD 2009-16-14, Amendment 39-15987 (74 FR 38901, August 5, 2009) (“AD 2009-16-14”)), whichever occurs later, do the inspection required by paragraph (k) of this AD.

(i) Retained Initial Inspection for Group 1 Configuration Airplanes, With No Changes

This paragraph restates the requirements of paragraph (k) of AD 2012-12-05, with no changes. For Group 1 airplanes identified in Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: Perform a detailed inspection for cracking of the intercostal web, attachment clips, and stringer splice channels; and a high frequency eddy current (HFEC) inspection for cracking of the stringer splice channels located forward and aft of the forward entry door; and do all applicable corrective actions before further flight; in accordance with Parts 1 and 2 of the Work Instructions of Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003, or Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or in accordance with Parts 1, 2, 4, and 5 of the Work Instructions of Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010. After September 9, 2009 (the effective date of AD 2009-16-14), and until July 23, 2012 (the effective date of AD 2012-12-05), Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010; may be used to accomplish the actions required by this paragraph. As of July 23, 2012, only Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010, may be used to accomplish the actions required by this paragraph.

(j) Retained Initial Inspection for Cargo Configuration Airplanes (Forward of the Forward Entry Door), With No Changes

This paragraph restates the requirements of paragraph (l) of AD 2012-12-05, with no changes. For Group 2 cargo airplanes identified in Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: Perform a detailed inspection for cracking of the intercostal webs and attachment clips located forward of the forward entry door, and do all applicable corrective actions before further flight, in accordance with Part 3 of the Work Instructions of Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003, or Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or in accordance with Part 3 of Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010. After September 9, 2009 (the effective date of AD 2009-16-14), and until July 23, 2012 (the effective date of AD 2012-12-05), Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010; may be used to accomplish the actions required by this paragraph. As of July 23, 2012, only Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010, may be used to accomplish the actions required by this paragraph.

(k) Retained Initial Inspection for Cargo Configuration Airplanes (Aft of the Forward Entry Door), With No Changes

This paragraph restates the requirements of paragraph (m) of AD 2012-12-05, with no changes. For Group 2 cargo airplanes identified in Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: Perform a detailed inspection for cracking of the intercostal webs and attachment clips located aft of the forward entry door, and do all applicable corrective actions before further flight, in accordance with Part 4 of the Work Instructions of Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or in accordance with Part 3 of Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010. As of July 23, 2012 (the effective date of AD 2012-12-05), only Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010, may be used to accomplish the actions required by this paragraph.

(l) Retained Repetitive Inspections, With No Changes

This paragraph restates the requirements of paragraph (n) of AD 2012-12-05, with no changes. Repeat the inspections required by paragraphs (i), (j), and (k) of this AD thereafter at intervals not to exceed 6,000 flight cycles after the previous inspection, or within 3,000 flight cycles after September 9, 2009, whichever occurs later.

(m) Retained Exceptions to Boeing Special Attention Service Bulletin 737-53-1204, With No Changes

This paragraph restates the requirements of paragraph (o) of AD 2012-12-05, with no changes. Do the actions required by paragraphs (g), (h), (i), (j), (k), and (l) of this AD by accomplishing all the applicable actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003; Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010; except as provided by paragraphs (m)(1) and (m)(2) of this AD. After September 9, 2009 (the effective date of AD 2009-16-14), and until July 23, 2012 (the effective date of AD 2012-12-05), Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010; may be used to accomplish the actions required by this paragraph. As of July 23, 2012, only Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010, may be used to accomplish the actions required by this paragraph.

(1) Where Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003; Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; or Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010, specifies to contact Boeing for repair instructions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (s) of this AD.

(2) Where Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003; or Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; specifies a compliance time relative to the date of a service bulletin, this AD requires compliance relative to September 9, 2009 (the effective date of AD 2009-16-14). Where Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003; or Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007; specifies a compliance time relative to the date of the initial release of a service bulletin, this AD requires compliance relative to November 1, 2005 (the effective date of AD 2005-20-03).

(n) Retained Exceptions to Boeing Alert Service Bulletin 737-53A1204, With No Changes

This paragraph restates exceptions to Boeing Alert Service Bulletin 737-53A1204 specified in paragraph (r) of AD 2012-12-05, with no changes.

(1) The access and restoration instructions identified in the Work Instructions of Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010, are not required by this AD. Operators may perform those actions in accordance with approved maintenance procedures.

(2) The use of Boeing Drawing 65-88700 is not allowed when accomplishing the actions required by this AD in accordance with the Work Instructions of Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010.

(o) Retained Initial and Repetitive Inspections of the S-15L Aft Intercostal and Cargo Barrier Net Fitting for Model 737-200C Series Airplanes, With No Changes

This paragraph restates the requirements of paragraph (s) of AD 2012-12-05, with no changes. For Group 2 airplanes identified in Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010: Before the accumulation of 15,000 total flight cycles, or within 4,500 flight cycles after July 23, 2012 (the effective date of AD 2012-12-05), whichever occurs later, do initial detailed and HFEC inspections for cracking of the S-15L aft intercostal between BS 348.2 and BS 360, and do a detailed inspection of the cargo barrier net fitting at the intercostal, in accordance with Figure 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1204, Revision 2, dated June 24, 2010. If any cracking is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (s) of this AD. Repeat the inspections thereafter at intervals not to exceed 6,000 flight cycles.

(p) Actions for Boeing Alert Service Bulletin 737-53A1240, Including New Repetitive Inspections of Certain Fastener Holes

(1) For airplanes identified as Group 1 and Group 3 in Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016: Except as required by paragraph (q) of this AD, at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016, do all applicable actions identified as “RC” (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016.

(2) For airplanes identified as Group 2 in Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016: Within 120 days after the effective date of this AD, do actions to correct the unsafe condition using a method approved in accordance with the procedures specified in paragraph (s) of this AD.

(q) Exceptions to Service Information Specifications

(1) Where Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016, uses the phrase “after the Revision 2 date of this service bulletin,” for purposes of determining compliance with the requirements of this AD, the phrase “after the effective date of this AD” must be used.

(2) Where Boeing Alert Service Bulletin 737-53A1240, Revision 2, dated November 2, 2016, specifies contacting Boeing, and specifies that action as RC: This AD requires using a method approved in accordance with the procedures specified in paragraph (s) of this AD.

(r) Credit for Previous Actions

This paragraph provides credit for the actions specified in paragraph (p) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Service Bulletin 737-53A1240, Revision 1, dated June 29, 2010, provided the conditions specified in paragraphs (r)(1) and (r)(2) of this AD are met and except as provided by paragraph (r)(3) of this AD. Boeing Alert Service Bulletin 737-53A1240, Revision 1, dated June 29, 2010, was incorporated by reference in AD 2012-12-05.

(1) Note 1 of paragraph 3.A of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1240, Revision 1, dated June 29, 2010, was disregarded when accomplishing the actions.

(2) Boeing Drawing 65-88700 was not used when accomplishing the actions in accordance with the Work Instructions of Boeing Alert Service Bulletin 737-53A1240, Revision 1, dated June 29, 2010.

(3) The access and restoration instructions identified in the Work Instructions of Boeing Alert Service Bulletin 737-53A1240, Revision 1, dated June 29, 2010, are not required. Operators are allowed to perform those actions in accordance with approved maintenance procedures.

(s) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Los Angeles Aircraft Certification Office (ACO) Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in paragraph (t)(1) of this AD. Information may be emailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(3) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO Branch, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(4) Except as required by paragraph (q)(2) of this AD: For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (s)(4)(i) and (s)(4)(ii) of this AD apply.

(i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or substep is labeled “RC Exempt,” then the RC requirement is removed from that step or substep. An AMOC is required for any deviations to RC steps, including substeps and identified figures.

(ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition.

(t) Related Information

(1) For more information about this AD, contact Galib Abumeri, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office (ACO) Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: [phone]; fax: [phone]; email: [e-mail].

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740; telephone [phone]; Internet https://www.myboeingfleet.com. You may view this referenced service information at the FAA, Transport Standards Branch, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.

Issued in Renton, Washington, on August 2, 2017.

Jeffrey E. Duven,

Director, System Oversight Division, Aircraft Certification Service.